Files
shields/lib/version.js
2017-10-26 16:31:13 -04:00

84 lines
2.3 KiB
JavaScript

/**
* Utilities relating to generating badges relating to version numbers. Includes
* comparing versions to determine the latest, and determining the color to use
* for the badge based on whether the version is a stable release.
*
* For utilities specific to PHP version ranges, see php-version.js.
*/
'use strict';
const semver = require('semver');
// Given a list of versions (as strings), return the latest version.
// Return undefined if no version could be found.
function latest(versions) {
let version = '';
let origVersions = versions;
versions = versions.filter(function(version) {
return (/[0-9]/).test(version);
});
try {
version = semver.maxSatisfying(versions, '');
} catch(e) {
version = latestDottedVersion(versions);
}
if (version === undefined) {
origVersions = origVersions.sort();
version = origVersions[origVersions.length - 1];
}
return version;
}
exports.latest = latest;
function listCompare(a, b) {
const alen = a.length, blen = b.length;
for (let i = 0; i < alen; i++) {
if (a[i] < b[i]) {
return -1;
} else if (a[i] > b[i]) {
return 1;
}
}
return alen - blen;
}
exports.listCompare = listCompare;
// === Private helper functions ===
// Take a list of string versions.
// Return the latest, or undefined, if there are none.
function latestDottedVersion(versions) {
const len = versions.length;
if (len === 0) { return; }
let version = versions[0];
for (let i = 1; i < len; i++) {
if (compareDottedVersion(version, versions[i]) < 0) {
version = versions[i];
}
}
return version;
}
// Take string versions.
// -1 if v1 < v2, 1 if v1 > v2, 0 otherwise.
function compareDottedVersion(v1, v2) {
const parts1 = /([0-9.]+)(.*)$/.exec(v1);
const parts2 = /([0-9.]+)(.*)$/.exec(v2);
if (parts1 != null && parts2 != null) {
const numbers1 = parts1[1];
const numbers2 = parts2[1];
const distinguisher1 = parts1[2];
const distinguisher2 = parts2[2];
const numlist1 = numbers1.split('.').map(function(e) { return +e; });
const numlist2 = numbers2.split('.').map(function(e) { return +e; });
const cmp = listCompare(numlist1, numlist2);
if (cmp !== 0) {
return cmp;
} else {
return distinguisher1 < distinguisher2? -1:
distinguisher1 > distinguisher2? 1: 0;
}
}
return v1 < v2? -1: v1 > v2? 1: 0;
}